# This file is part of SpiffWorkflow.
#
# SpiffWorkflow is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 3.0 of the License, or (at your option) any later version.
#
# SpiffWorkflow is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301  USA

from threading import Lock

class mutex(object):

    def __init__(self):
        self.lock = Lock()

    def lock(self):
        raise NotImplementedError

    def test(self):
        has = self.lock.acquire(blocking=False)
        if has:
            self.lock.release()

        return has

    def testandset(self):
        return self.lock.acquire(blocking=False)

    def unlock(self):
        self.lock.release()
